Exceptional scheduler is winner for Pilkington Special Glass

Scheduling is an important aspect of any batch production process, but nowhere more so than in ultra-specialist glass production. Indeed for Pilkington Special Glass, it’s more complex than scheduling suggests, critical though this is. Also key – and intimately inter-dependent – are dynamic production re-allocation, re-planning and the rest, driven by both highly variable customer demand and the complexities of as-produced glass quality as assessed by the firm’s post-production laboratory. This is an exceptional story. Fact is, many of Pilkington Special Glass’ products are unique, as are the production processes and plant involved. According to the company, very few have the technology: few can produce this purity of high-spec glass outside the laboratory environment. Markets served include optical, ophthalmic and sunglasses as well as the space and nuclear industries. Logistics controller Mike Large takes up the story: “It’s like Alchemy: we’re making this glass at the cutting edge. Like any other company, we have a forecast and a manufacturing plan – but 30 seconds later we might change it.” Why? “We make such pure, high-tech glass– we measure impurities down to very tight specifications because that changes the optical properties and material characteristics of the glass – that the slightest contamination of raw material, for example, can mean we can’t physically make the planned product. “Or we find two weeks after production that the product we made didn’t make the grade. When that happens we need to be able to respond to what’s happening in the process on the fly.” Additionally, many of the glasses take days to produce, and change-over and set-up times can also run into several days. Large says scheduling mistakes and failed production can be measured hundreds of thousands of pounds over a year. As for forecasting and planning, Large says: “A difficulty we have is that a large part of production goes to the Far East – to camera makers for example. But we’re dealing with a large number of people all taking different amounts of the same glass – with different specifications. They run stocks down to zero, and you might not hear from them for a year: then they re-order.” And he refers to a situation recently where a two day old urgent order for 30 tonnes of an optical glass increased overnight to 70 –with the same delivery date. At the other extreme, big government contracts are know years ahead, and these too have to be scheduled into production capacity. Clearly, much of the demand is unpredictable, and history too random for useful forecasting. And on top of this there were the usual raw material and finished goods stock issues and difficulties with plant and departmental bottlenecks, particularly with some glasses taking several weeks across the production to testing prior to release phase. The firm required exceptional integrated scheduling IT. Large recalls how it used to be done. “The entire scheduling system was paper-based. Any changes on the main Gantt Chart to one job meant all the other jobs had to be manually updated. It wasn’t uncommon for a second change to be required before the first was even halfway through. And as soon as these changes were finished, the works orders on the floor also had to be manually updated.” Large knew Pilkington needed IT support, and that it would have to be exceptional. He says he looked at everything from enterprise (ERP) to planning and scheduling systems. Eventually, he found Preactor. “Most off-the-shelf systems only offered 50-60% of what I wanted: their solutions were too inflexible for our process environment.” And they either laughed at talk of ‘tailoring’ or wanted “£100,000 for doing it”, he says. “With Preactor in its basic form I got 75% – and after working with their partner Resource Management Systems (RMS), this went up to 95%.” In fact, Preactor’s flexible Open Planning Board technology, coupled with RMS’ development team has produced a custom solution which fits the bill. It comprises a Preactor finite capacity scheduling system, with three Preactor Viewers on the plant floor. Any changes made to any schedule can now be viewed instantaneously from the plant floor by the planning department and production, as well as senior sales and marketing people. As for integration with the other functions, RMS implemented a data link between Preactor and Pilkington’s bespoke Unix-based customer and stock management systems, allowing real time two-way flow of data so that scheduling scenarios automatically generate customer and stock information, instantly updating when changes on the schedule are actioned. It’s now been in about four months, and Large says it’s been a great success. “Preactor is very quick,” he says. “If you change production say from glass A to glass B, Preactor looks at raw materials and recipes on the Unix system and throws out a new plan for material use and re-ordering. But it also looks at the forecasts against what actually happens: we see the sales pattern and the sales and operations plan and can change the forecast. Everything appears on the Preactor screens.” While this has helped to reduce stock problems, it has also helped smooth internal and supply chain bottlenecks. Large says that reports from Preactor emailed direct to departments, or via its intranet to suppliers mean the firm can now dynamically re-schedule plant to make short and long lead time glass types to minimise internal packing, warehousing and despatch problems, as well as material supply problems. Given the hour by hour changes that this industry requires, Large says the time and financial savings even in this one area look set to be substantial. And he claims that Pilkington’s reduced reaction time to production order changes has already significantly increased its ability to fulfil delivery promises, and reduce lead times. Large says he has every faith in Preactor as his main system. Pilkington is now looking at extending the system – to include coverage of people and resource management, as well as engineering and machinery management. He also expects to go further and install direct links into shopfloor data collection systems.